Fibromyalgia (FM) is a chronic condition marked by widespread pain, psychological distress, and significant societal costs. This study evaluates the feasibility of a mobile health (mHealth) application designed to support cognitive-behavioral therapy for FM by enabling real-time tracking of patient-reported outcomes and adaptive treatment modifications within public health care settings. Thirty-six adults with FM participated in this feasibility study, which assessed the app's usability, acceptability, and clinical utility for both patients and therapists. Results demonstrated high usability ratings (87.63 for patients, 88.75 for therapists) and adherence rates (67.9 percent of requested evaluations completed), confirming the app's practicality and engagement potential. The app generated 1,348 clinical alarms during the intervention, providing actionable insights that allowed therapists to tailor treatments dynamically. This study highlights the role of mHealth technologies in enhancing psychological care through data-driven, real-time monitoring, and treatment personalization. Small but notable reductions in depression levels underscore the app's potential to improve psychological outcomes. By fostering engagement and facilitating personalized care, this approach advances the integration of digital health tools in chronic disease management, offering a scalable model for enhancing behavioral interventions in public health systems.